CHANGES += `loadBefore vs GC` fix + undeprecated the package

Suggested by @d-maurer and @dataflake

https://github.com/zopefoundation/tempstorage/pull/16#pullrequestreview-698960847
https://github.com/zopefoundation/tempstorage/issues/8#issuecomment-873940781

CHANGES.rst

@@ -4,7 +4,9 @@ Changelog
 5.2 (unreleased)
 ----------------
 
-- Nothing changed yet.
+- Package is now officially undeprecated because the data corruption issue -
+  that was the reason for its deprecation - has been understood and fixed. See
+  (`#16 <https://github.com/zopefoundation/tempstorage/issues/16>`_).
 
 
 5.1 (2019-08-15)

README.rst

@@ -5,12 +5,3 @@ A storage implementation which uses RAM to persist objects, much like
 MappingStorage. Unlike MappingStorage, it needs not be packed to get rid of
 non-cyclic garbage and it does rudimentary conflict resolution. This is a
 ripoff of Jim's Packless bsddb3 storage.
-
-**Please note: Usage of this package is deprecated, as it is known to randomly lose data, especially with Zope 4.**
-
-For a detailed discussion see `#8 <https://github.com/zopefoundation/tempstorage/issues/8>`_ as well as `#12 <https://github.com/zopefoundation/tempstorage/issues/12>`_
-
-To replace server-side sessions, cookies are probably your best bet, as these also get rid of any denial of service problems that server side sessions are vulnerable to.
-
-If you need server side storage of sessions, consider using a normal store rather than tempstorage for your session data.
-For details and suggestions see `this discussion in the pull request <https://github.com/zopefoundation/tempstorage/pull/14#issuecomment-520318459>`_ as well as the discussion in the aforementioned bug reports as well as `the discussion in Zope about the removal of the generated configuration <https://github.com/zopefoundation/Zope/pull/684>`_.

src/tempstorage/TemporaryStorage.py

@@ -19,7 +19,6 @@ resolution.
 This is a ripoff of Jim's Packless bsddb3 storage.
 """
 import bisect
-from logging import getLogger
 import warnings
 import time
 
@@ -38,8 +37,6 @@ CONFLICT_CACHE_GCEVERY = 60
 # keep history of recently gc'ed oids of length RECENTLY_GC_OIDS_LEN
 RECENTLY_GC_OIDS_LEN = 200
 
-LOG = getLogger('TemporaryStorage')
-
 
 class ReferenceCountError(POSException.POSError):
     """ Error while decrementing a reference to an object in the commit phase.
@@ -85,13 +82,6 @@ class TemporaryStorage(BaseStorage, ConflictResolvingStorage):
 
         _conflict_cache_maxage -- age at whic conflict cache items are GC'ed
         """
-        deprecation_warning = """\
-DEPRECATED: Usage of the package tempstorage is deprecated, as it is known to randomly lose data.
-Especially on Zope 4. For details see https://github.com/zopefoundation/tempstorage/issues/8
-and https://github.com/zopefoundation/tempstorage
-"""
-        LOG.warning(deprecation_warning)
-        warnings.warn(deprecation_warning, DeprecationWarning)
 
         BaseStorage.__init__(self, name)